Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1st Term / PHA115 > Week 15 / GI system 1 > Flashcards

Week 15 / GI system 1 Flashcards

1
Q

Q: What is the gastrointestinal (GI) system?

A

A: The GI system is a group of organs that work together to break down ingested food into smaller, absorbable nutrient molecules. These nutrients can then be absorbed into the blood and distributed to all the cells in the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Q: What are the main functions of the gastrointestinal (GI) system?

A

A: The GI system:

Digests or biochemically breaks down ingested food into small, simple nutrient molecules.

Absorbs and transfers nutrient molecules, electrolytes, and water from ingested food into systemic circulation.

Makes preformed organic nutrient molecules available to body cells to be used as sources of fuel or energy.

Provides building blocks for the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Q: What are the 5 basic digestive processes performed by the gastrointestinal (GI) system?

A

A: The 5 basic digestive processes performed by the GI system are:

Motility
Secretion
Digestion
Absorption
Storage & Elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Q: What is motility in the digestive system, and what are its types?

A

A: refers to muscular contractions that mix and move the contents of the digestive tract forward.

There are two types of digestive motility:

Propulsive Movements - Propel or push contents forward through the digestive tract.

Mixing Movements - Mix food with digestive juices to promote digestion and facilitate absorption of digested food.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Q: What is secretion in the GI system, and what are the types of secretions involved?

A

A: Secretion in the GI system refers to digestive juices secreted into the GI tract in response to specific neural or hormonal stimulation.

These secretions consist of water, electrolytes, and specific organic constituents (enzymes, mucus, etc.).

There are two types of secretions:

Exocrine Secretions - Secreted into the lumen of the GI tract, including:
Water, HCl (hydrochloric acid), HCO₃⁻ (bicarbonate), bile, lipase, pepsin, amylase, trypsin, and histamine.

Endocrine Secretions - Secreted into the bloodstream, including:
Gastrin, secretin, CCK (cholecystokinin), VIP (vasoactive intestinal peptide), and somatostatin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Q: What is digestion in the GI system, and how is it accomplished?

A

A: Digestion is the biochemical breakdown of complex foodstuffs into smaller, absorbable units through enzyme-mediated hydrolysis.

The breakdown of complex foodstuffs results in:

Carbohydrates → Monosaccharides
Proteins → Amino acids
Fats → Glycerol and fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Q: What is absorption in the GI system, and where does it occur?

A

A: Absorption is the transfer of small digested units, along with water, vitamins, and electrolytes, from the GI tract into the blood or lymph.
It occurs largely and most completely in the small intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Q: What are the two main components of the gastrointestinal (GI) system?

A

A: The two main components of the GI system are:

Alimentary canal: A long, continuous hollow tube stretching from the mouth to the anus (approximately 30 feet long).

Accessory organs and glands: Including the salivary glands, liver, and pancreas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Q: What are the main components of the alimentary canal?

A

A: The alimentary canal is continuous from the mouth to the anus and consists of the following parts:

Mouth
Pharynx
Oesophagus
Stomach
Small intestine:
Duodenum
Jejunum
Ileum
Large intestine:
Caecum
Appendix
Colon
Rectum
Anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Q: What are the accessory digestive organs?

A

A: The accessory digestive organs include:
Salivary glands
Exocrine pancreas
Biliary system
Liver
Gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Q: How is the alimentary canal functionally divided?

A

A: The alimentary canal is divided into three main parts:

Upper part:
Mouth, oesophagus, and stomach
Serves as food intake and initial digestion site.

Middle part:
Small intestine (duodenum, jejunum, ileum)
Main site for digestion and absorption.

Lower part:
Large intestine (caecum, colon, rectum)
Serves as the storage channel for undigested material.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Q: What are the 4 layers of the alimentary canal?

A

Mucosa Layer
Submucosa Layer
Muscularis Externa Layer
Serosa Layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Q: What is the composition of the mucosa layer in the alimentary canal?

A

A: Epithelial cells, connective tissue, and smooth muscle cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Q: What are the functions of the mucosa layer?

A

A:

Protects against pathogens.

Secretes mucus, digestive enzymes, and hormones.

Absorbs digested nutrients.

Undergoes rapid cell division and regeneration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Q: What is the composition of the submucosa layer?

A

A: Dense connective tissue with blood and lymphatic vessels, lymphoid follicles, and nerve fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Q: What are the functions of the submucosa layer?

A

A:

Provides distensibility and elasticity to the digestive tract.

Glands secrete digestive enzymes.
Nerve plexus helps regulate gut motility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Q: What is the structure of the muscularis externa layer?

A

A: Inner circular smooth muscle layer and outer longitudinal smooth muscle layer.

18
Q

Q: What are the functions of the muscularis externa layer?

A

A:

Facilitates mixing and movement of food (peristalsis and segmentation).
Intrinsic nerve plexus helps regulate gut motility.

19
Q

Q: What is the composition of the serosa layer?

A

A: Connective tissue and epithelial covering, continuous with the mesentery.

20
Q

Q: What is the function of the serosa layer?

A

A: Secretes a slippery serous fluid for lubrication and reduces friction between digestive organs and surrounding viscera.

21
Q

Q: What role do interstitial cells of Cajal (pacemaker cells) play in digestive function?

A

A: They generate slow-wave potentials (BER) that produce spontaneous rhythmic electrical activity, helping to regulate the digestive process.

22
Q

Q: How do intrinsic nerve plexuses (ENS) regulate digestive function?

A

A: They control GI muscle contraction or relaxation, influencing digestive motility.

23
Q

Q: What is the role of extrinsic nerves (ANS) in digestive function?

A

A: They can increase or decrease GI contraction and secretion, influencing digestive activity.

24
Q

Q: How do gastrointestinal hormones regulate digestive function?

A

A: They increase or decrease GI contraction and secretion, impacting digestive processes.

25
Q

Q: What are the types of local sensory receptors involved in regulating digestion?

A

A: Chemoreceptors, mechanoreceptors, and osmoreceptors, which help monitor changes in the GI environment and modulate digestive function.

26
Q

Q: What is the purpose of mastication (chewing) in digestion?

A

A: It aids in the mechanical breakdown of larger food units and mixes food with saliva, which contains salivary amylase for partial digestion of starch.

27
Q

Q: What are the functions of saliva in digestion?

A

A: Saliva moistens ingested food, lubricates it, and exerts an antibacterial effect. It also contains salivary amylase, which helps in partial digestion of starch.

28
Q

Q: What are the two stages of deglutition (swallowing)?

A

A: The oropharyngeal stage and the oesophageal stage.

29
Q

Q: What is the function of the uvula during swallowing?

A

A: The uvula prevents food from entering the nasal cavity by moving upward to close off the nasopharynx.

30
Q

Q: What happens during the oropharyngeal stage of swallowing?

A

A: The bolus of food is pushed by the tongue into the pharynx. The epiglottis covers the glottis to prevent food from entering the trachea, and the bolus moves through the pharynx into the esophagus.

31
Q

Q: What role does the epiglottis play during swallowing?

A

A: The epiglottis covers the glottis (opening to the trachea) to prevent food from entering the respiratory tract.

32
Q

Q: What happens to the upper esophageal sphincter during swallowing?

A

A:

(a) It is contracted before swallowing.
(b) It relaxes during swallowing to allow the bolus to pass into the esophagus.
(c) It contracts again after the bolus passes through.

33
Q

Q: How does the bolus move from the pharynx to the esophagus?

A

A: The bolus moves through the pharynx and into the esophagus as the upper esophageal sphincter relaxes, and peristalsis begins to move the bolus downward.

34
Q

Q: What are the two main intrinsic nerve plexuses in the gastrointestinal system?

A

A: The two main intrinsic nerve plexuses are the myenteric nerve plexus and the submucosal nerve plexus.

35
Q

Q: What is the function of the myenteric nerve plexus?

A

A: The myenteric nerve plexus primarily controls the muscle contractions of the muscularis externa, coordinating peristalsis and segmentation.

35
Q

Q: What are the components of the mucosa layer in the alimentary canal?

A

A: The mucosa consists of three components:

Epithelium
Lamina propria (connective tissue)
Muscularis mucosae (smooth muscle layer).

36
Q

Q: What is the function of the submucosal nerve plexus?

A

A: The submucosal nerve plexus regulates the secretion of digestive enzymes and controls the function of the glands in the submucosa.

37
Q

Q: What is the composition of the muscularis externa layer in the alimentary canal?

A

A: The muscularis externa consists of an inner circular muscle layer and an outer longitudinal muscle layer.

38
Q

Q: What are the components of the serosa layer?

A

A: The serosa consists of an epithelium (mesothelium) and underlying connective tissue. It provides lubrication and reduces friction between organs.

39
Q

Q: What is the role of the duct of a gland outside the alimentary canal?

A

A: The duct transports digestive secretions from accessory glands (like salivary glands, liver, or pancreas) into the lumen of the alimentary canal.

40
Q

Q: What does the submucosa layer contain?

A

A: The submucosa contains glands, blood vessels, lymphatic vessels, nerve fibers, and sometimes Mucosa-associated lymphoid tissue (MALT).

1st Term / PHA115 (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions